Hydrocarbon fluids, e.g. crude oil, contain different organic moieties with diverse functionalities including asphaltenes, saturates, aromatics, long and short chain organic acids, amines, and/or others. Injection water or produced water related to oil production contains both ions and organic substances. Analyzing reservoir-related fluids provides insight with respect to potential problems related to a hydrocarbon fluid reservoir. Data from the analysis can be useful in understanding the quality and economic value of produced fluids from the reservoir and can guide production strategy. Depending on the application, analysis to help understand the composition of hydrocarbon fluid and/or water produced or injected may be used to enable improved control over the production and/or injection operation. The fluids may be analyzed at the wellhead or in a laboratory, although the results of surface-based analyses may be compromised due to the very different conditions between the surface and the subterranean location.